A display method based on SharpMap technology is introduced in this paper. With this method, over 2300 discrete rainfall points can be shown in choroplethic map. This method reads geographic information data and basic information of station to generate map layers and data layers, then read precipitation data to generate choroplethic map through the analysis of the contour line. At last, these layers will be displayed in a certain order to show the precipitation data. This method also can be applied to analysis other meteorological data.